Metal extrusion



Nov. 24, 1964 w, sc 3,158,262

METAL EXTRUSION Original Filed Nov. 1. 1961 United States Patent3,158,262 METAL EXTRUSlON Albert W. crihner, 6 Country Club Road,Darien, Conn.

Original application Nov. 1, 1961, Ser. No. 149,300, now Patent No.3,146,886, dated Sept. 1, 1964. Divided and this application Sept. 6,1963, Ser. No. $117,140

4 (Ilairns. (Cl. 27--9) This is a division of my copending applicationentitled Metal Extrusion, Serial No. 149,300 filed on Nov. 1, 1961,issued as US. Patent No. 3,146,886, dated September 1, 1964. a

The instant invention relates to a novel method and apparatus for dieexpressing metals and the like whereby a given size extruded product maybe produced by a relatively small size press.

One object of the invention is to provide an extrusion process whichutilizes a series of die expressing strokes each of which serves toextrude only a portion of the work material and to form an unextrudedportion of the work material to a sectional profile correspondingsubstantially to the shape of the extrusion orifice; each such formedunextruded work portion being advanced through said orifice before theinitiation of the next succeeding die expressing stroke.

Another object of the invention is to provide a novel extrusionapparatus having at least one extrusion ram adapted to extrude and formsuccessive billet portions and having a feed ram adapted to advance theformed unextruded work material through the extrusion orifice during theperiod between the extrusion of the successive billet portions, theinner end of said extrusion ram being formed so as to correspond inprofile to an adjacent portion of the extrusion orifice.

Other objects of the invention will become apparent as the disclosureprogresses.

In the drawings:

FIG. 1 is a plan view in partial section of one embodiment of anapparatus that is capable of carrying out the instant extrusiontechnique.

FIG. 2 is similar to FIG. 1 and shows an active condition of the pressrams.

FIG. 3 is a sectional elevational view taken along section line 3-3 ofFIG. 2.

FIG. 4 is a front elevational view showing part of the apparatus of FIG.1.

FIGS. 1-4 show an illustrative embodiment of the instant inventionwherein an 1 beam type of extruded product is to be die expressed. Itwill be understood however that various extruded shapes may be dieexpressed in accordance with the hereinafter described extrusiontechnique by appropriately changing the shape of the work forming toolsurfaces so as to correspond to the particular sectional contour desiredfor the extruded product.

Referring to FIG. 1 there is shown a container 111 of general T-shapedconfiguration and having a rectangular cross sectioned billet receivingchamber 11 formed therein. Two narrow laterally opposed coextensiverectangularly cross sectioned ram guide chambers 12 and 13 are formed bycontainer walls. A pair of extrusion rams 14 and 15 are slidably mountedin said chambers 12 and 13 respectively and a feed ram 16 is slidablymounted in the container at the upper end of said chamber 11 asillustrated in FIG. 1. The rams are cross sectionally shaped 'so as toclosely fit their respectively associated chambers. As shown in FIG. 3the heights H of the rams 14, and 16 are substantially the same.Operatively mounted in the container walls opposite ram 16 is a die 17having an orifice 2t} uniformly formed 3,153,262 Patented Nov. 24, 19642 therethrough and being sectionally shaped like an I-beam section. Theheight H, FIG. 4, of said orifice is also substantially the same as thesaid height H, FIG. 3, of said rams. The inner ends of rams 14 and 15are shaped so that when said rams are moved to their respective innerlimits of movement the shape of the gap therebctween, in a plane normalto the die axis, is not only substantially the same as the FIG. 4 shapeof the orifice 20 but is also substantially axially coextensivetherewith as is illustrated by FIGS. 3 and 4. The upper and lower limits21 and 22, FIG. 4, of the orifice 20 are substantially coextensive withthe respectively adjacent upper and lower wall surfaces 23 and 24, FIG.3, of the container 113.

In operation after a billet 25 has been inserted in the box-like chamber11 the feed ram 16 is advanced until the lead end of the billet isseated against the inner fiat face of the extrusion die. Thereafterwhile ram 16 is held stationary the extrusion rams 14 and 15 are eachadvanced through extrusion strokes E as shown in FIG. 2 so as to dieexpress a portion 26 of the work material. The rams .14 and 15 are thenwithdrawn to their FIG. 1 positions and the feed ram 16 is advancedthrough a first relatively short incremental feed stroke F, FIG. 2.During the stroke F the unextruded portion of the work material that wasjust previously formed between the inner contoured ends of the narrowrams 14 and 15 will readily slide through the extrusion orifice 26 inthat this formed unextruded portion of the work has substantially thesame sectional shape as that of the die orifice due to the said relativecontouring of the inner ends of rams 14 and 15. The length of the strokeF is substantially equal to the width of the rams 14 and 15, i.e.,stroke F is just sufficient to bring the flat wide unformed andunextruded shoulder-portion of the billet against the ilat inner facesof die 17 and adjacent portions of the container walls. Thereafter rams14 and 15 are again advanced through similar extrusion strokes to dieexpress a further portion of the billet material. These alternateextrusion strokes E and feeding strokes F are continued until the usablepart of the work billet has been extruded. The instant techniquerequires only the application of repetitive light extrusion strokes withthe very light alternate feeding strokes and such will therebynecessitate a relatively small press frame, low overall working forcesand a relatively small power drive means to produce and accommodate thedesired extrusion pressures in the container and die orifice.

In the cold extrusion of hard metals the use of a proper lubricant isnecessary to avoid excessive tool wear, etc. It is known to use avitreous material for hot extrusion of 'steel, however, such knownlubricants do not suifice for cold extrusion below say 400 degrees F. Alubricant which may be used between the work metal and the tool surfacesduring a cold extrusion operation in the manner of use of said vitreouslubricants is an oxide of arsenic such as arsenic trioxide. Alsopotassium arsenate and beryllium fluoride may be utilized. Other arsenictype lubricants which are suitable here are silver arsenate, arseniousoxide, arsenic disulfide and benzene be coated on the outer surfaces ofthe tools and/ or work billet. Here the outer layer of work materialmelted by the exothermic action during the extrusion operation willprovide a viscous lubricant film between the Work and tools.

While several embodiments of the invention have been shown and describedit will be apparent to those skilled in the art that numerous variationsand modifications may be made in the particular construction and methodwithout departing from the underlying principles of the invention. It istherefore desired by the following claims to include within the scope ofthe invention all such variations and modifications wherebysubstantially the results of the invention may be obtained by the use ofsubstan tially the same or equivalent means or techniques.

The invention claimed is:

1. A method of extruding metal: comprising the steps of operativelyconfining a Work billet adjacent an extrusion die orifice;

laterally compressing the region of the Work billet adjacent saidextrusion die orifice so that a portion of this billet region is dieexpressed through said orifice; forming the remaining unextruded portionof said billet region so as to have substantially the same sectionalshape as said die orifice and so as to be located in substantiallycoextensive alignment with said orifice; advancing all of the unextrudedbillet material toward said orifice so that said formed portion of saidbillet region slides through the corresponding shaped extrusion orificewith substantially no extrusion action taking place; and

sequentially repeating said compressing, forming and advancing steps tocomplete the extrusion of the billet material.

2. In an extrusion press:

a container having a work receiving chamber formed therein;

a feed ram slidably mounted in said container for work feed movementinto said chamber; an extrusion die formed with an extrusion orifice andoperatively mounted at one end of said chamber; and

at least one laterally disposed extrusion ram slidably mounted in saidcontainer for movement into said chamber and toward the axis of said dieorifice at a location immediately adjacent to the front operative faceof said die; the inner end of said ram being contoured so as tocorrespond to the adjacent portion of the profile of the die orifice,and the inner limit of movement of the extrusion ram being such as toposition the contoured surfaces of said inner ram end in substantiallycoextensive alignment with respect to the said adjacent portion of theprofile of said die orifice.

3. Apparatus as defined by claim 2 wherein the heights of said chamber,rams and the die orifice are substantially the same.

4. Apparatus as defined by claim 3: additionally comprising a secondextrusion ram slidably mounted in said container in opposed relationwith respect to the first mentioned extrusion rain, said secondextrusion ram having an inner end that is also contoured so as tocorrespond to the adjacent portion of said die orifice, said extrusionrams being disposed substantially normal with respect to the axis ofsaid die orifice.

References Cited by the Examiner UNITED STATES PATENTS 2,708,770 5/55Herres et al 18-12 2,902,714 9/59 Johnson 18-12 2,975,893 3/61 Johnson207-2 MICHAEL V. BRINDISI, Primary Examiner.

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2. IN AN EXTRUSION PRESS: A CONTAINER HAVING A WORK RECEIVING CHAMBERFORMED THEREIN; A FEED RAM SLIDABLY MOUNTED IN SAID CONTAINER FOR WORKFEED MOVEMENT INTO SAID CHAMBER; AN EXTRUSION DIE FORMED WITH ANEXTRUSION ORIFICE AND OPERATIVELY MOUNTED AT ONE END OF SAID CHAMBER;AND AT LEAST ONE LATERALLY DISPOSED EXTRUSION RAM SLIDABLY MOUNTED INSAID CONTAINER FOR MOVEMENT INTO SAID CHAMBER AND TOWARD THE AXIS OFSAID DIE ORIFICE AT A LOCATION IMMEDIATELY ADJACENT TO THE FRONTOPERATIVE FACE OF SAID DIE; THE INNER END OF SAID RAM BEING CONTOURED SOAS TO CORRESPOND TO THE ADJACENT PORTION OF THE PROFILE OF THE DIEORIFICE, AND THE INNER LIMIT OF MOVEMENT OF THE EXTRUSION RAM BEING SUCHAS TO POSITION THE CONTOURED SURFACES OF SAID INNER RAM END INSUBSTANTIALLY COEXTENSIVE ALIGNMENT WITH RESPECT TO THE SAID ADJACENTPORTION OF THE PROFILE OF SAID DIE ORIFICE.